| 摘要 |
926,921. Radio navigation. STANDARD TELEPHONES & CABLES Ltd. Jan. 22, 1960 [Jan. 28, 1959], No. 2394/60. Drawings to Specification. Class 40 (7). A known type of radio beacon (VOR) radiating an effectively rotating signal pattern together with an omni-directional signal is arranged to radiate a second omni-directional signal so that the range and bearing of a mobile craft provided with apparatus which transmits a signal on the occurrence of the craft of a given phase relationship between the rotating signal pattern and the second omni-directional signal may be obtained by employing the signal received from the mobile craft as a brightening pulse for a P.P.I. display at the beacon station, the circular scan of which is effected at the frequency of effective rotation of the signal pattern and the radial scan by pulses of repetition frequency equal to the frequency of the second omni-directional signal. The mobile craft is, additionally, provided with known means for deriving its azimuthal bearing relative to the beacon by phase comparison of the rotating and first omni-directional signals. |
